• Natural Product Sciences
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• 제1권1호
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• pp.1-4
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• 1995

MeOH extract of the leaves of Xanthium strumarium L. were found to have cytotoxic activities against five human tumor cell lines. Cytotoxicity-guided chromatographic fractionation led to the isolation of the ${\alpha}-methylene$ containing sesquiterpenes, xanthatin, 8-epi-xanthatin and 8-epi-tomentosin. 8-epi-Xanthatin was found to be far more cytotoxic than 8-epi-tomentosin, which lacks the conjugated enone moiety present in 8-epi-xanthatin.

• 공업화학
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• 제28권1호
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• pp.17-22
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• 2017

본 총설에서는 마이크론 사이즈 이하 제품에 대한 최적화적인 화학공정의 스케일업을 위한 전략을 소개한다. 최적화된 화학공정의 스케일업을 위해 구해야 할 스케일업 인자의 정의와 이를 도출하는 방법을 소개하였으며, 특히 무반응 시스템, 유반응 시스템으로 분류하여 각각에 대해 서로 다른 스케일업 인자를 찾은 기준을 소개하고, 예시를 들어 논의하였다. 본지에서 소개된 스케일업 인자를 구하는 방법론이 마이크론 사이즈 이하 제품에 대한 화학공정을 스케일업하고자 하는 엔지니어들에게 초기 지침서가 될 것으로 기대된다.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2208-2212
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• 2009

Oxidation of cycloalkenes with $O_2$ promoted by heterogeneous bis(acetylacetonato) cobalt (II) complex catalyst which can be recycled has been performed under mild conditions. It was found that $\beta$-ionone, cyclohexene, 1-methylcyclohexene, and $\alpha$-ionone were efficiently oxidized with $O_2$ in the presence of Co (II) complex and butyraldehyde at $55\;{^{\circ}C}$. A simple treatment of the resulting products led to epoxides as predominant products and a small amounts of allylic oxides, the chemoselectivity for the former being 82.1 - 90.8% with a 70.6 - 98.6% substrate conversion. On the other hand, oxidation of 1-phenylcyclohexene, 1-cyclohex-1-enylethan-1-one, $\alpha$-pinene, and $\beta$-pinene gave allylic oxides as major products.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2006년도 학술발표대회 논문집
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• pp.48-54
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• 2006

In this thesis, accelerated life test (ALT) method and procedure for rubber O-ring are applied to assure specified reliability of the products at guaranteeing the life of the products. Rubber O-ring is parts that keep intensity or make machine operation smoothly on attrition portion of machine and is used to prevent that oil is leaked. Usually. Rubber O-ring used NBR that is copolymer of acrylonitrile and butadiene. this are superior oil resistance, heat resistance, durability of abrasion, cold resistance, chemical resistance etc. The accelerated life test model for rubber O-ring are developed using the relationship between stresses and life characteristics of products. Using the accelerated life test method and the acceleration life test equipment which is developed, we performed life test, collected life data and analyzed the results of tests. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3421-3422
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• 2010

• Bulletin of the Korean Chemical Society
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• 제34권5호
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• pp.1589-1591
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• 2013

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.657-660
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• 2013

• Bulletin of the Korean Chemical Society
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• 제13권6호
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• pp.654-658
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• 1992

Photolysis of 1-phenyl-1,3,5-hexatriynes in deaerated tetrahydrofuran gave photoreduction and photoaddition products, while photolysis of 1-phenyl-1,3,5-hexatriynes in deaerated alcoholic solvents (methanol, i-propanol) yielded dark red products, probably oligomers or decomposition products of reactants, as exclusive major products. A plausible mechanism for the reaction is proposed.

• 자원리싸이클링
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• 제26권3호
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• pp.3-16
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• 2017

화학촉매제품은 석유화학공정, 대기오염방지시설, 자동차 배기가스 정화 장치 등 다양한 분야에 적용되고 있다. 국내외 화학촉매 시장은 매년 증가하고 있는 추세이며, 그에 따라 발생되는 폐촉매량도 증가하고 있다. 탈황 폐촉매, 자동차 폐촉매 등 대부분의 사용 후 화학촉매제품은 유가금속을 함유하고 있어 경제적 가치와 자원 확보 측면에서 매우 중요한 순환자원이다. 이에 일부 도시광산업체를 통해 유가금속을 회수하는 재자원화 공정이 상용화 되어 있고, 사용 후 SCR 탈질 촉매제품은 일부 재제조를 통해 자원순환되고 있다. 이에 본 논문에서는 사용 후 화학촉매제품의 재자원화 산업 지원 정책 수립의 기초자료로 활용이 가능하도록 주요촉매제품별 국내 발생량 및 재자원화 현황을 조사 분석하였으며, 사용 후 화학촉매제품의 자원순환 활성화를 위한 발전과제를 제시하였다.

• Corrosion Science and Technology
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• 제18권4호
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• pp.138-147
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• 2019

Pipes and components of the secondary system in the pressurized water reactor (PWR) are mainly comprised of manufactured carbon steel. Thus, the generated carbon steel corrosion products are transported into the steam generator and deposited, thereby deteriorating the integrity of the steam generator. Environmental condition in the secondary system of the PWRs differs across different locations. So, the corrosion rate and types of corrosion products depend on specific locations in the secondary system. In this study, the quantity and chemical compositions of corrosion products generated in various locations that vary in different temperatures and chemistry conditions were investigated. As a result of evaluating the PWR "Unit A" that is in current operation, the amount of corrosion products generated in the section of high temperature feedwater system was identified as the largest source in the secondary system. Major components of corrosion products were iron oxides such as magnetite, hematite, and lepidocrocite.